The need for this invention arose from problems of obtaining flat modulation response in frequency synthesizers having nonlinear, wide bandwidth Voltage Controlled Oscillators (VCOs).
Others have attempted to solve the problem by utilizing dual response adaptive loops--one response optimized for frequency acquisition and one response optimized for flat modulation response--or, alternatively, by linearizing the VCO.
However, the problems were not entirely solved because adaptive loops that are optimized are optimized at a narrow loop bandwidth and, alternatively, linearization of the VCO is relatively expensive.
The instant invention solves the problem by flattening the modulation response by providing constant loop gain through compensation of the nonlinear VCO gain with a substantially reciprocal or multiplicatively inverse gain.
This invention represents a measurable advance over the prior art and over this technical field by providing a constant gain, wide bandwidth frequency synthesizer.